Remove number of unused styles imports

plugins/PerObjectSettingsTool/PerObjectSettingsPanel.qml

@@ -3,7 +3,6 @@
 
 import QtQuick 2.2
 import QtQuick.Controls 2.15
-import QtQuick.Controls.Styles 1.2
 
 import UM 1.5 as UM
 import Cura 1.0 as Cura

resources/qml/MonitorButton.qml

@@ -3,7 +3,6 @@
 
 import QtQuick 2.2
 import QtQuick.Controls 1.1
-import QtQuick.Controls.Styles 1.1
 import QtQuick.Layouts 1.1
 
 import UM 1.5 as UM

resources/qml/Preferences/Materials/MaterialsBrandSection.qml

@@ -3,7 +3,6 @@
 
 import QtQuick 2.7
 import QtQuick.Controls 1.4
-import QtQuick.Controls.Styles 1.4
 import QtQuick.Layouts 1.3
 
 import UM 1.5 as UM

resources/qml/Preferences/Materials/MaterialsTypeSection.qml

@@ -3,7 +3,6 @@
 
 import QtQuick 2.7
 import QtQuick.Controls 1.4
-import QtQuick.Controls.Styles 1.4
 import QtQuick.Layouts 1.3
 
 import UM 1.5 as UM

resources/qml/PrinterOutput/HeatedBedBox.qml

@@ -3,7 +3,6 @@
 
 import QtQuick 2.10
 import QtQuick.Controls 1.4
-import QtQuick.Controls.Styles 1.4
 import QtQuick.Layouts 1.3
 
 import UM 1.2 as UM

resources/qml/PrinterOutput/MonitorSection.qml

@@ -3,7 +3,6 @@
 
 import QtQuick 2.10
 import QtQuick.Controls 1.4
-import QtQuick.Controls.Styles 1.4
 import QtQuick.Layouts 1.3
 
 import UM 1.2 as UM

resources/qml/PrinterOutput/OutputDeviceHeader.qml

@@ -1,7 +1,6 @@
 import QtQuick 2.2
 
 import QtQuick.Controls 1.1
-import QtQuick.Controls.Styles 1.1
 import QtQuick.Layouts 1.1
 
 import UM 1.2 as UM